People working on metallic or conductive pipes, such as, for example, but not limited to, pipes used in the oil and gas industry, are exposed to electrical current as part of their daily jobs. One of the culprits relates to the Electrical Code (NEC) allowing grounding of electrical systems to pipes in building. Stray electrical current is passed through the metallic pipes inside the buildings through to the pipes outside. Another culprit relates to the repair and maintenance of the pipes. When welding is required, electrical current must be generated to perform the welding operation.
Service crews repairing, replacing or updating the pipes must handle the exposed metal pipes and can be electrically shocked by the undesired or stray current traveling through the pipes.
In addition, when welding, grounding of electrical circuits is a safety practice that is documented in various codes and standards. A typical arc welding setup may consist of several electrical circuits. Applying and maintaining proper grounding methods within the welding area is important to promote electrical safety in the workplace. Associated processes such as plasma cutting will also benefit from proper grounding.
Welding machines that utilize a flexible cord and plug arrangement or those that are permanently wired into an electrical supply system contain a grounding conductor. The grounding conductor connects the metal enclosure of the welding machine to ground.
The purpose of connecting the equipment enclosure to ground is to ensure that the metal enclosure of the welding machine and ground is at the same potential. When they are at the same potential, a person will not experience an electrical shock when touching the two points. Grounding the enclosure also limits the voltage on the enclosure in the event that insulation should fail within the equipment.
The current carrying capability of the grounding conductor is coordinated with the overcurrent device of the electrical supply system. The coordination of ampacity allows the grounding conductor to remain intact even if there is an electrical fault within the welding machine.
The welding circuit consists of all conductive material through which the welding current is intended to flow. Welding current flows through the welding machine terminals, welding cables, workpiece connection, gun, torch, electrode holder and workpiece. The welding circuit is not connected to ground within the welding machine, but is isolated from ground.
According to ANSI Z49.1, “Safety in Welding, Cutting and Allied Processes,” the workpiece must be grounded. The workpiece must be connected to a suitable ground. The ground connection should be independent or separate from the welding circuit connection.
While there are currently arcane grounding systems and procedures in place, the systems and procedures are difficult to implement and are not routinely followed. It would, therefore, be beneficial to provide a grounding system and components which are easy and effective to use. It would also be beneficial to provide a grounding system and components which can be easily transported and minimizes the time and effort to set up and take down the system. It would also be beneficial to provide sufficient grounding when field welding is done to allow the welding apparatus to properly perform and to protect the operator of the welding machine from exposure to the harmful electrical current.